Process for breaking petroleum emulsions



Patented Jan. 27, 1953 PROCESS FOR BREAKING PETROLEUM EMULSIONS Melvin De Groote, University City, Mo., assignor to Petrolite Corporation, a corporation of Dela- Ware No Drawing. Application May 14, 1951, Serial No. 226,312

11 Claims.

The present invention is a continuation-inpart of my copending applications, Serial Nos. 104,801 filed July 14, 1949 (now Patent 2,552,528, granted May 15, 1951), 109,619 filed August 10, 1949 (now Patent 2,552,531, granted May 15, 1951), and 107,381 filed July 28, 1949 (now Patent 2,552,530, granted May 15, 1951). This invention relates to petroleum emulsions of the water-in-oil type that are commonly referred to as cut oil, roily oil, emulsified oil, etc., and which comprise fine droplets of naturallyoccurring waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion.

One object of my invention is to provide a novel process for breaking or resolving emulsions of the kind referred to. Another object of my invention is to provide an economical and rapid process for separating emulsions which have been prepared under controlled conditions from mineral oil, such as crude oil and relatively soft Waters or weak brines. Controlled emulsification and subsequent demulsification under the conditions just mentioned are of significant value in removing impurities, particularly inorganic salts from pipeline oil.

Demulsification as contemplated in the present application includes the preventive step of commingling the demulsifier with the aqueous component which would or might subsequently become either phase of the emulsion, in absence of such precautionary measure. Similarly, such demulsifier may be mixed with the hydrocarbon component.

The demulsifying agent employed in the present process is a fractional ester obtained from a polycarboxy acid and a polyhydro-oxylated -material obtained by the oxypropylation of a polyamino reactant.

More specifically the present process involves the use of a demulsifying agent which is a fractional ester obtained from a polycarboxy acid and a compound derived in turn by the oxypr'opyla tion of propylenediamine or an equivalent 'diamine as hereinafter specified, having four terminal hydroxyl radicals or the equivalent, i. e., labile hydrogen atoms susceptible to oxyalkylation. Indeed, as pointed out hereinafter the diamine derivative need only have a plurality of reactive hydrogen atoms, i. e., 2 or more.

The most suitable raw material is propylenediamine as such or after treatment with several moles of ethylene oxide or glycide, or a combination of the two, and particularly propylenediamine after being treated with one to four or even five or six moles of ethylene oxide. The initial diamino compound must be characterized y 1 (c) Having 2 amino nitrogen atoms and preferably both being basic;

(b) Free from any radical having 8 or more carbon atoms in an uninterrupted group;

(0) Must be water-soluble; and

(0!) Have a plurality of reactive hydrogen atoms, preferably at least 3 or 4.

Needless to say, the most readily available reactant, to wit, propylenediamine, has 4. reactive hydrogen atoms and this would still be true after reaction with ethylene oxide, for instance, 1 to 4 moles of ethylene oxide. However, reaction with glycide would provide as many as 8 reactive hydrogen atoms provided that the molal ratio was 4 to 1, i. e., 4 moles of glycide for one mole of diamine. On the other hand, if propylene diamine were treated with a mole of an alkylating agent so as to introduce-an alkyl radical such as methyl, ethyl, propyl, butyl, hexyl, heptyl, or the like, or an aryl radical such as a phenyl radical, then and in that event the number of reactive hydrogen atoms might be decreased to as few as two and still be acceptable for the instant purpose. If an alkyl radical or an alicyclic radical, such as a cyclohexyl radical, or an alkylaryl radical such as a benzyl radical, were introduced the basicity of the nitrogen atom would not be materially effected. However, the introduction of a phenyl radical would, of course, markedly affect the basicity of the nitrogen atom. For obvious reasons my choice is as follows:

(a) The use of propylenediamine rather than any substituted. propylenediamine as described;

(1)) The use of propylenediamine after treatment with 1 to 5 moles of ethylene oxide although a modestly increased amount of ethylene oxide can be used in light of what is said hereinafter; or

(c) The use of a derivative obtained from propylenediamine after reaction with glycide, or a mixture of ethylene oxide and glycide.

Since reaction of propylenediamine with propylene oxide is invariably involved and since this oxyalkylation step is substantially the same as the use of ethylene oxide or glycide, for purpose of brevity further reference simply will be made to propylenediamine as illustrating the procedure, regardless of what particular reactant is selected. It is not necessary to point out, 'of course, that the substituted propylenediamine, i. e., those where an alkyl, alicyclic, aryl-alkyl, or aryl group has been introduced can similarly be subjected to reaction with ethylene oxide,'glycide, or a combination of the two.

I also want to point out it is immaterial whether the initial oxypropylation step involves hydrogen attached to oxygen or hydrogen attached to nitrogen. The essential requirement is that it be a labile or reactive hydrogen atom. Any substituent radical present must, of course, have less than 8 uninterrupted carbon atoms in a single group. 7

More specifically, then, the present invention is concerned with a process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being the acidic fractional acylation products of (A) a polycarboxy acid and (B) high molal oxypropylation derivatives of monomeric diamino compounds, which monomeric diamino compounds are free from any radical having at least 8 uninterrupted carbon atoms, have molecular weights not over 800, at least a plurality of reactive hydrogen atoms, are water soluble, have the nitrogen atoms linked by a propylene chain, and which oxypropylation derivatives are Water insoluble and kerosene soluble, have a molecular weight between 2000 and 30,000, a ratio of proylene oxide per initial reactive hydrogen atom within the range of '7 to 70, in which the monomeric diamino compound represents not more than 20% by weight, the molecular Weights and proportions stated being based upon the assumption of complete reaction of the propylene oxide and the monomeric diamino compound and on an average statistical basis and with the further proviso that the ratio of polycarboxy acid to high molal oxypropylation derivatives be one mole of acid for each hydroxyl radical present in the latter. The products are undoubtedly largely fractional esters but may, and probably do, include ester salts and acidic amido derivatives.

Thus, reference to the products as fractional esters may be and probably is an over-simplification for reasons which are obvious on further examination. It is pointed out subsequently that prior to esterification the alkaline catalyst can be removed by addition of hydrochloric acid. Actually the amount of hydrochloric acid added is usually sufficient and one can deliberately employ enough acid, not only to neutralize the alkaline catalyst, but also to neutralize the amino nitrogen atom or convert it into a salt. Stated another way, a trivalent nitrogen atom is converted into a pentavalent nitrogen atom, i. e., a change involving an electrovalency indicated as follows:

wherein I-IX represents any strong acid or fairly strong acid such as hydrochloric acid, nitric acid, sulfuric acid, a sulphonic acid, etc., in whih H represents the acidic hydrogen atom and X represents the anion. Without attempting to complicate the subsequent description further it is. obvious then that one might have esters or one might convert the esters into ester salts as described. Likewise another possibility is that under certain conditions one could obtain amides. The explanation of this latter fact resides in this observation. In the case of an amide, such as acetamide, there is always a question as to whether or not oxypropylation involves both amido hydrogen atoms so as to obtain a hundred per cent yield of the dihydroxylated compound. There is some evidence to at least some degree that a monohydroxylated compound is obtained under some circumstances with one amido hydrogen atom remaining without change.

n r anat on which ha somet mes. a r ar d n the oxvpropyl tion of nitro n-containing compounds particularly such as acetamid i th t h mole ule appe rs t de mpo nder co t o s o analys s. and. unsaturat seems to appear simultaneously. One suggestion has been that one hydroxyl is lost by dehydration and that this ultimately causes a break in the 4 molecule in such a way that two "new hydroxyls are formed. This is shown-after a fashion in a highly idealized manner in the following way:

CH3 CH3 H 4, I I l 11 no 0- -CXOC-C-COH H n H 11 CH3 CH3 H l l l In the above formulas the large X is obviously not intended to signify anything except the central part of a large molecule, whereas, as far as a speculative explanation is concerned, one need only consider the terminal radicals, as shown. Such suggestion is of interest only because it may be a possible explanation of how an increase in hydroxyl value does take place which could be interpreted as a decrease in molecular weight. This matter is considered subsequently in the final paragraphs of Part 2. This same situation seems to apply in the oxypropylation of at least some polyalkylene amines and thus is of significanoe in the instant situation.

As far as the herein described compounds are concerned it would be absolutely immaterial excent that one would have in part a compound which might be the fractional ester and might also represent an amide in which only one carboxyl radical of a polycarboxylated reactant was involved. By and large, it is believed that the materials obtained are obviously fractional esters, for reasons which are apparent in light of what has been said and in light of what appears hereinafter.

For convenience, what is said hereafter will be divided into four parts:

Part 1 is concerned with the preparation of the oxypropylation derivatives of propylenediamine or equivalent initial reactants;

Part 2 is concerned with the preparation of the esters from the oxypropylated derivatives;

Part 3 is concerned with the nature of the oxypropylation derivatives insofar that a cogeneric mixture is invariably obtained, and

Part 4 is concerned with the use of the products herein described as demulsifiers for breaking Water-in-oil emulsions.

PART 1 For a number of well known reasons equipment, whether laboratory size, semi-pilot plant size, pilot plant size, or large scale size, is not as a rule designed for a particular alkylene oxide. Invariably and inevitably, however, or particularly in the case of laboratory equipment and pilot plant size the design is such as to use any of the customarily available alkylene oxides, i. e,. ethylene oxide, propylene oxide, butylene, glycide, epichlorohydrin, styrene oxide, etc. In the subsequent description of the equipment it becomes obvious that it is adapted for oxyethylation as well as oxypropylation.

Oxypropylations are conducted under a wide variety of conditions, not only in regard to presence or absence of catalyst, and the kind of catalyst, but also in regard to the time of reaction, temperature of reaction, speed of reaction, pressure during reaction, etc. For instance, oxyalkylations can be. conducted at temperatures up to approximately 200 C. with pressures in about the same range up to about 200 pounds per square inch. They can be conducted also at temperatures approximating the boiling point of water or slightly. above, as for example 95 to 120 C. Under such circumstances the pressure will be less than 30 pounds per square inch unless some special procedure is employed as is sometimes the case, to wit, keeping an atmosphere of inert gas such as nitrogen in the vessel during the reaction. Such low-temperaturelow reaction rate oxypropylations have been described very completely in U. S. Patent No. 2,448,664 to H. R. Fife et al., dated September 7, 1948. Low temperature, low pressure oxypropylations are particularly desirable where the compound being subjected to oxpyropylation contains one, two or three points of reaction only, such as monohydric alcohols, glyools and triols.

The initial reactants in the instant application contain at least 2 reactive hydrogens and for this reason there is possibly less advantage in using low temperature oxypropylation rather than high temperature oxypropylation. However the reactions do not go too slowly and this particular procedure was used in the subsequent examples.

Since low pressure-low temperature-low-reaction-speed oxypropylations require considerable time, for instance, 1 to 7 days of 24 hours each to complete the reaction they are conducted as a rule Whether on a laboratory scale, pilot plant scale, or large scale, so as to operate automatically. The prior figure of seven days applies especially to large-scale operations. I have used conventional equipment with two added automatic features; (a) a solenoid controlled valve which shuts off the propylene oxide in event that the temperature gets outside a predetermined and set range, for instance, 95 to 120 C., and (b) another solenoid valve which shuts 01f the propylene oxide (or for that matter ethylene oxide if it is being used) if the pressure gets beyond a predetermined range, such as 25 to 35 pounds. Otherwise, the equipment is substantially the same as is commonly employed for this purpose where the pressure of reaction is higher, speed of reaction is higher, and time of reaction is much shorter. In such instances such automatic controls are not necessarily used.

Thus, in preparing the various examples I have found it particularly advantageous to use laboratory equipment or pilot plant which is designed to permit continuous oxyalkylation whether it be oxypropylation or oxethylation. With certain obvious changes the equipment can be used also to permit oxyalkylation involving the use of glycide where no pressure is involved except the vapor pressure of a solvent, if any; which may have been used as a diluent; 1 w

As previously pointedout the method of using propylene oxide is thesame as ethylene oxide. This point is emphasized only for the reason that the apparatus is so designed and constructed as to use either oxide. l

The oxypropylation procedure'employed in the preparation of the oxyalkylated derivatives has been uniformly the same, particularly in light of the fact that a continuous automatically-controlled procedure was employed. In this procedure the autoclave was a conventional autoclave made of stainless steel and having a capacity of approximately gallonsanda working .ment as far as propylene oxide goes unless there is a reaction of explosive violence involved. due to 6 accident. The autoclave was equipped with the conventional devices and openings, such as the variable-speed stirrer operating at speeds from 50 R. P. M. to 500 R. P. M.; thermometer well and thermocouple for mechanical thermometer; emptying outlet; pressure gauge, manual vent line; charge hole for initial reactants; at least one connection for introducing the alkylene oxide, such as propylene oxide or ethylene oxide, to the bottom of the autoclave; along with suitable devices for both cooling and heating the autoclave, such as a cooling jacket, and, preferably, coils in addition thereto, with the jacket so arranged that it is suitable for heating with steam or cooling with water and further equipped with electrical heating devices. Such autoclaves are, of course, in essence small-scale replicas of the usual conventional autoclave used in oxyalkylation procedures. In some instances in exploratory preparations an autoclave having a smaller capacity, for instance, approximately 3 /2 liters in one case and about 1% gallons in another case, was used.

Continuous operation, or substantially continuous operation, was achieved bythe use of a separate container to hold the alkylene oxide being employed, particularly propylene oxide. In conjunction with thesmaller autoclaves, the container consists essentially of a laboratory bomb having a capacity of about one-half gallon, or somewhat in excess thereof. In some instances a larger bomb was used, to wit, one having a capacity of about one gallon. This bomb was equipped, also, with an inlet for charging, and an eductor tube going to the bottom of the container so as to permit discharging of alkylene oxide in the liquid phase to the autoclave. A bomb having a capacity of about 60 pounds was used in connection with the 15-gallon autoclave. Other conventional equipment consists, of course, of the rupture disc, pressure gauge, sight feed glass, thermometer connection for nitrogen for pressuring bomb, etc. The bomb was placed on a scale during use. The connections between the bomb and the autoclave were flexible stainless steel hose or tubing so that continuous weighings could be made without breaking or making any connections. This applies also to the nitrogen line, which was used to pressure the bomb reservoir. To the extent that it was required, any other usual conventional procedure or addition which provided greater safety was used, of course, such as safety glass protective screens, etc.

Attention is directed again to what has been said previously in regard to automatic controls which shut off the propylene oxide in event temperature of reaction passes out of the predetermined range or if pressure in the autoclave passes out ofpredetermined range.

With this particular arrangement practically all oxypropylations become uniform in that the reaction temperature was held within a few de grees of any selected point, for instance, if C. was selected as the operating temperature the maximum point would be at the most C. or 112 C., and the lower point would be 95 or possibly 98 C. Similarly, the pressure washeld at approximately 30 pounds maximum within a 5-pound variation one way or the other, but might drop to practically zero, especially where no solvent such as x-ylene is employed; Thespeed of'i'eaction was comparatively slow under such conditions as compared with oxyalkylations at 200 C. Numerous reactions were conducted in which the time varied from-one day (24 hours) up to three days (72 hours), for completion of the final member of a series. In some instances the reaction may take place in considerably less time, i. e., 24 hours or less, as far as a partial oxypropylation is concerned. The minimum time recorded was about a 6-hour period in a single step. Reactions indicated as being complete in 7 or 8 hours may have been complete in a lesser period of time in light of the automatic equipment employed. In the addition of propylene oxide, in the autoclave equipment as far as possible the valves were set so all the propylene oxide if fed continuously would be added at a rate so that the predetermined amount would react within the first hours of the 8-hour period or two-thirds of any shorter period. This meant that if the reaction was interrupted automatically for a period of time for pressure to drop or temperature to drop the predetermined amount of oxide would still be added in most instances well within the predetermined time period. Sometimes where the addition was a comparatively small amount in a 8-hour period there would be an unquestionable speeding up of the reaction, by simply repeating the example and using 4, 5 or 6 hours instead of 8 hours.

When operating at a comparatively high temperature, for instance, between 150 to 200? C., an unreacted alkyl'ene oxide such as propylene oxide, makes its presence felt in the increase in pressure or the consistency of a high pressure. However, at a low enough temperature it may happen that the propylene oxide goes in as a liquid. If so, and if it remains unreacted there is, of course, an inherent danger and appropriate steps must be taken to safeguard against this possibility; if need be a sample must be withdrawn and examined for unreacted propylene oxide. One obvious procedure, of course, is to oxypropylate at a modestly higher temperature, for instance, at 140 to 150 C. Unreacted oxide affects determination of the acetyl or hydroxyl value of the hydroxylated compound obtained.

The higher the molecular weight of the compound, i. e., towards the latter stages of reaction, the longer the time required to add a given amount of oxide. One possible explanation is that the molecule, being larger, the opportunity for random reaction is decreased. Inversely, the lower the molecular weight the faster the reaction takes place. For this reason, sometimes at least, increasing the concentration of the catalyst does not appreciably speed up the reaction, particularly when the product subjected to oxyalkylation has a comparatively high molecular weight. However, as has been pointed out previously, operating at a low pressure and a low temperature even in large scale operations as much as a week or ten days time may lapse to obtain some of the higher molecular weight derivatives from monohydric or dihydric materials.

In a number of operations the counterbalance scale or dial scale holding the propylene oxide bomb was so set that when the predetermined amount of propylene oxide had passed into the reaction the scale movement through a time operating device was set for either one to two hours so that reaction continued for 1 to 3 hours after the final addition of the last propylene oxide and thereafter the operation was shut down. This particular device is particularly suitable for use on larger equipment than laboratory size autoclaves, to wit, on semi-pilot plant or pilot plant size, as well as on large scale size. This final stirring period is intended to avoid the presence of unreacted oxide.

In this sort of operation, of course, the temperature range was controlled automatically by either use of cooling water, steam, or electrical heat, so as to raise or lower the temperature. The pressuring of the propylene oxide into the reaction vessel was also automatic insofar that the feed stream was set for a slow continuous run which wasshut off in case the pressure passed a predetermined point as previously set out. All the points of design, construction, etc., were conventional including the gauges, check valves and entire equipment. As far as I am aware at least two firms, and possibly three, specialize in autoclave equipment such as I have employed in the laboratory, and are preparedto furnish equipment of this same kind. Similarly pilot plant equipment is available. This point is simply made as a precaution in the direction of safety. Oxyalkylations, particularly involving ethylene oxide, glycide, propylene oxide, etc., should not be conducted except in equipment specially designed for the purpose.

It is to be noted in the present instance one may or may not have basic nitrogen atoms present. For example, if a phenyl radical is attached to each nitrogen atom the initial diamine is substantially nonbasic. However, if one employs propylenedia-mine there are present two basic nitrogen atoms and thus the addition of an alkaline catalyst can be eliminated in the early stages of oxypropylation or oxyethylation. This is illustrated subsequently by the fact that oxypropylation was permitted to go through the first stage without the addition of alkaline catalyst.

Example 1a The particular autoclave employed was one with a capacity of about 15 gallons or on the average of about pounds of reaction mass. The speed of the stirrer could be varied from to 350 R. P. M. The initial charge was 7.25 pounds of propylenediamine. In the initial charge .75 pound of caustic soda was added notwithstanding the fact that the first oxypropylation would have taken place satisfactorily without any added alkalinity. The reaction pot was flushed out with nitrogen, the autoclave sealed, and the automatic devices set for injecting 87.5 pounds of propylene oxide in 13 hours. The oxide was injected at about the rate of 6 or 7 pounds per hour. The pressure regulator was set for a maximum pressure of 35-37 pounds per square inch. However, in this particular step and in all succeeding steps the pressure never got over 33.5 pounds per square inch. In fact, this meant that the bulk of the reaction could take place and did take place at an appreciably lower pressure. This comparatively low pressure was the result of the fact that the reactant per se was basic and a fair amount of catalyst had been added. The propylene oxide was added comparatively slowly and, more important, the selected temperature range was 250-255 F. (moderately higher than the boiling point of water). The initial introduction of propylene oxide was not started until the heating devices had raised the temperature to approximately the boiling point of water. At the completion of the reaction the sample was taken and oxypropylation proceeded as in Example 2a,

immediately following.

Example 2 a pounds of reaction mass identified as Example 1a, preceding, and equivalent to 3.90 pounds of polyamine, 47.20 pounds of propylene oxide, and .4 pound of caustic soda, were permitted to remain in the reaction vessel. No further catalyst was added. The mixture was then reacted with 43.75 pounds of propylene oxide. The oxypropylation was conducted in substantially 10 Example 1a was soluble in water, soluble in xylene, but insoluble in kerosene; Example 2a Was emulsifiable in water, soluble in xylene, but insoluble in kerosene; Example 3a was insoluble the same manner as in regard to temperature and in water, soluble in xylene; and insoluble-in keropressure as in Example la, preceding. The time sene; Examples 4a and 5a were both insoluble period, however, was considerably shorter insofar in water, soluble in xylene and soluble in kerosene. that much less oxide was added. The addition The final product, i. e., at the end of the oxywas made at about the rate of 11 or 12 pounds propylation step, was apt to be either a straw per hour. The oxypropylation was conducted in color, or sometimes it would have a more definite substantially the same manner as far as temperreddish amber or a distinct dark-amber tinge. ature and pressure were concerned as in Example In the later stages the product was invariably la, preceding. At the end of the reaction period water-insoluble and kerosene-soluble. This is part of the reaction mass with withdrawn and characteristic of all the products obtained from oxypropylation continued as described in Ex- 15 the diamino products herein described. Needample 3a, following. less to say if more ethylene oxide radicals were Example 3a introduced into the initial raw material the initial product is more water-soluble and one must 52.25 pounds of the reaction mass identified go to higher molecular weights to produ t as Example preceding. and equivalent to insolubility and kerosene-solubility, for instance, u d of the polyam n 49.89 pou ds f pr p molecular Weights such as 10,000 to 12,000 or more ene oxide, and .22 pound of caustic soda, we on a theoretical basis, and 5000 to 6000, or even permitted to remain in the autoclave. 36 pounds more, on a hydroxyl molecular weight basis. If, 0f D py n Oxide re introduced during a however, the initial diamino compound is treated hour period. No additional catalyst was added. with one or more or perhaps several moles of The conditions of reaction as o a temperature butylene oxide then the reverse eiiect is obtained and pressure were concerned were substantially d t, t k 1 propylene id t pmduce the same a in Example Preceding At e water-insolubility and kerosene-solubility. These e0mp1eti0n 0f the reaction P f the r ac o products were, of course, alkaline due in part mass was withdrawn and the remainder subto the residual caustic soda employed. This jected to further yp py s described in would also be the case if sodium methylate were Example 4a, following. used as a catalyst.

Emmpze 4 i ing of insolugility in water or solubility 45 pounds of the reaction mass identified as 13 ay g i igg igh 2 32: 2? gg ggg i Example 3a, preceding, were permitted to remain in a test tube with Water for instance 3 in the autoclave. No additional catalyst was to 5% approximatoly bazsed 0n the added. Conditions in regard to temperature and water present i 0 pressure were supstamlanyfiie Same as m E Needless to say, there is no complete conversion ample 1a, preceding. In this instance the oxide 4 40 of propylene oxide into the desired hydroxylated was added in a 6-hour period. The amount of compounds This is f indicated by the fact that ox1de added was 18 pounds. It was added at the theoretical molecula I ht about the rate of 3 /2 pounds per hour. At the r 81g based'on tlstical average is greater than the molecular end of the reaction period part of the reaction Wei ht c 1 1 t d b 1 mass was withdrawn and the remainder subjected g cu e y usua methods on of to further oxypropylation as described in Exacetyl or hydr9Xy1 Value Actually there Is no completely satisfactory method for determining ample 5a, following.

Example 5a 49.13 pounds of reaction mass identified as Example 4a, preceding, were permitted to remain o in the autoclave. No additional catalyst was added. 1'7 pounds of propylene oxide were introduced in an 8-hour period. The rate was approximately 2 pounds per hour. The conditions of temperature and pressure were substantially the same as in Example 1a, preceding. This particular oxypropylation series was stopped at this point.

What has been said herein is presented in tabular form in Table I immediately following with some added information as to molecular weight and as to solubility of the reaction product in water, xylene, and kerosene.

molecular weights of these types ofcompounds with a high degree of accuracy when the molecular weights exceed 2,000. In some instances the acetyl value or hydroxyl value serves as satis factorily as an index to the molecular weight as any other procedure, subject to the above limitations, and especially in the higher molecular weight range. If any difliculty is encountered in the manufacture of the esters as described in Part 2 the stoichiometrical amount of acid or acid compound should be taken which corresponds to the indicated acetyl or hydroxyl value. This matter has been discussed in'the literature and is a matter of common knowledge and requires no further elaboration. In fact, it is illustrated by some of the examples appearing in the patent previously mentioned.

TABLE I Composition Before Composition at End M. Max by Max. Pres Ex. Tune No. amine gxirtie Cat?- di lIieo. imigie gxide (llatig g t 2, 5 Hrs.

m m ys o m m ys lbs lbs lbs. Wt. lbs lbs. lbs.

la. 7. 25 970 7. 25 87. 75 75 564 250-255 35-37 13 2a. 3. 9O 47. 20 40 1, 800 3. 9O 90. 95 40 670 250255 35-37 4 311. 2. 14 49. 89 22 3, 040 2. 14 85. 89 22 1, 210 250-255 35-37 6 4a.. 1. O9 43. 11 4, 274 1. O9 61. 80 11 1, 530 250-255 35-37 6 5G. 4.8. 20 O8 5, 734 85 65. 20 O8 2, 055 250-255 35-37 8 chloric acid gas is to be used as a catalyst.

PART 2.

V As previously pointed out the present invention isconcerned with acidic esters obtained from the oxypropylated derivatives described in Part 1, immediately preceding, and polycarboxy acids, particularly tricarboxy acids like citric and dicarboxy acids such as adipic acid, phthalic acid, or anhydride, succinic acid, diglycollic acid,'sebacic acid, azelaic acid, aconitic acid, maleic acid or anhydride, citraconic acid or anhydride,.maleic acid or anhydride adducts as obtained by the Diels-Alder reaction from products such as maleic anhydride, and cyclopentadiene. Such acids should be heat stable so they are not decomposed during esterification. They may contain as many as 36 carbon atoms as, for example, the acids obtained by dimerization of unsaturated fatty acids, unsaturated monocarboxy-fatty acids, or unsaturated monocarboxy acids having 18 carbon atoms. pended claims obviously includes the anhydrides or any other obvious equivalents. "My preference, however, is to use polycarboxy acids having not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) from polycarboxy acids and glycols or other hydroxylated compounds is well known. In the present instance the hydroxylated compounds obtained as described in Part 1, preceding, contain nitrogen atoms which may or may not be basic. Thus, it is probable particularly where there is a basic nitrogen atom prescut that salts may be formed but in any event under conditions described the salt is converted into an ester; This is comparable to similar reactions involving the esterification of triethanolamine. Possibly the addition of an acid such as hydrochloric acid if employed for elimination of the basic catalyst also combines with the basic nitrogen present to form a salt. however, such procedure does not affect conventional esterification procedure as described here- 111.

Needless to say, various compounds may be used such as the low molal ester, the anhydride, the acyl chloride, etc. However, for purpose of economy it is customary to use either the acid or the anhydride. A conventional procedure is employed. On a laboratory scale one can employ a resin pot of the kind described in U. S. Patent No. 2,499,370, dated March 7, 1950 to De Groote & 'Keiser, and particularly with one more opening to permit the use of a porous spreader if hydro- Such device or absorption spreader consists of minute alundumthimbles which are connected to a glass tube. One can add a sulfonic acid such as paratoluene sulfonic acid as a catalyst. There is some objection to this because in some instances there is some evidence that this acid catalyst tends to decompose or rearrange the oxypropylated compounds, and particularly likely to do so if the esterification temperature is too high. In the case of polycarboxy acids such as diglycollic acid, which is strongly acidic there is no need to add any catalyst. The use of hydrochloric acid gas has one advantage over paratoluene sulfonic acid and that is that at the end of the reaction it can be removed by flushing out with nitrogen, whereas there is no reasonably convenient means available of removing the paratoluene sulfonic acid-or other sulfonic acid employed. If hydrochloric acid is employed one need only pass the gas through at an exceedingly slow ratesdasto'keep the reaction mass acidic. Only a trace of acid Reference to the acid in the hereto ap- In any event,

need be present...

I have employed hydrochloric acid gasor the aqueous acid itselfto eliminate the initial basic material. My preference, however, is to use no catalyst'whatsoever:

- The products obtained inPart'l preceding may contain a basic catalyst. As a general'procedure I have added an amount of half-concentrated hydrochloric acid considerably in excess of what is required to neutralize the residual catalyst.

The mixture is shaken thoroughly and allowed to stand overnight. It is then filtered and refluxed with the xylene present until the water can be separated in a phase-separating trap. As soon as the product is substantially free from water the distillation stops. This preliminary step can be carried outin the flask to be used for esterification. If there is any further deposition of sodium chloride. during thereflux. stage needless to say a second filtration may? be 'required. In any event the ,neutral or, slightly acidic solution of thefoxypropylated derivatives described in Part 1 is then diluted furtherwith sufiicient xylene, decalin,- petroleum. solvent, .or the like, so that one has obtained approximately a 45% solution. To this solution there is added a polycarboxylated reactant as previously described, such as phth'alic anhydride, succinic'acid or anhydride, diglycollic acid, etc. The mixture is refluxed until esterification is complete as indicated by elimination of water or drop .in carboxyl value. Needless to say, if one produces a half-ester from an anhydride such as phthalic anhydride, no water is eliminated. However, if it is obtained from diglycollic acid, for example, water is eliminated. All such procedures are conventional and have been sothoroughly described in the literature that further consideration will be limited to a few examples and a comprehensive table.

Other procedures for eliminating the basic residual catalyst, if anyycan'be employed. For example, the oxyalkylation can be conducted in absence of a solvent or the solvent removed after oxypropylation. Such oxypropylation end product can then be acidified with just enough concentrated hydrochloric acid to just neutralize the residual basic catalyst. To this product one can then add a small amount of anhydrous sodium sulfate (sufficient in quanttiy to take upany water that is present) and then subject the'mass to centrifugal force so as'to eliminate the hydrated sodium sulfate and probably the sodium chloride formed. The clear somewhat viscous dark-amber liquid so obtained may contain a small amount of sodium sulfate or sodium chloride but, in any event, is perfectly acceptable for esterification in the manner described.

It is to be pointed out that the products here described are not polyesters inthe sense that there is a plurality of both diamino radicals and acid radicals; the 'product'is characterized by having only one diamino radical.

In some instances and, in fact, in many instances I have found that in spite of the dehydration methods employed above that a mere trace of water still'comes through and that this mere trace of water certainly interferes with the acetyl or hydroxyl value determination, at least when a number of conventional procedures are used and may retard esterification, particularly where there is no sulfonic acid or hydrochloric acid present as a catalyst. Therefore, I have preferred to use the following procedure: I have employed about 200 grams of the polyhydroxylated compound as described in Part 1,

13 preceding; I have added about 60 grams of benzene, and then refluxed this mixture in the glass resin pot using a phase-separating trap until the benzene carried out all the water sification the solvent might just as well be allowed to remain. If the solvent is to be removed by distillation, and particularly vacuum distillation, then the high boiling aromatic present as water of solution or the equivalent. petroleum solvent might well be replaced by Ordinarily this refluxing temperature is apt to some more expensive solvent, such as decalin be in the neighborhood of 130 to possibly 150 or an alkylated decalin which has a rather de- C. When all this water or moisture has been finite or close range boiling point. The removal removed I also withdraw approximately 20 of the solvent, of course, is purely a conventional grams or a little less benzene and then add the To procedure and requires no elaboration. required amount of the carboxy reactant and In a number of examples instead of using also about 150 grams of a high boiling aromatic Solvent #7-3 I found it more convenient to use petroleum solvent. These solvents are sold by xylene, one reason being the xylene could be various oil refineries and. as far as solvent effect removed readily for examination of the solventact as if they were almost completely aromatic 15 free material. Reference is made to Examples in character. Typical distillation data in the 7b through 2927. In these instances Solvent particular type I have employed and found #7-3 could be used instead of xylene, or a mixvery satisfactory is the following: ture of the two could have been used. This l 4 o 1s the case particularly where the oxypropylated 5 ml 2 0%) g 242 g derivative showed decreased water-solubihty. a However, where the product showed significant 10 ml., 209 C. ml., 248 C. 15 m1 C m1 C water-solubility the diificulty arose that at the 20 m1" 216 0" end of 1116 esterification reaction the solvent 3 and resultant or reaction mass was not homo- 25 ml., 220 C. ml., 260 C. 25 30 mL mL geneous. Thus, 1n Examples 11) through 3b two- 35 ml 230 C m1 270 c thirds of the solvent was xylene and one-third 40 ml 234 C 1" was methanol. These solvent proportions could 45 6 6 be varied without objection within reasonable limits. Two-thirds of the indicated amount of After this material is added. reflux is con- 0 solvent was indicated as xylene and after all tinned a O e. s a a hlgher temperature, the water was removed the non-homogeneous to about t0 l If the Y mixture was rendered homogeneous by the adreactant s an anhydrlde needless to Say no dition of methanol equal to 50% of the original water of react o pp 1f the Qarboxy xylene. These solvent properties could be varied actant is an acid, water of reactlon should 35 Somewhat t t change, t object, being appear and should be eliminated at the above merely to eliminate water in presence of waterreaction t p If it is not ellmmated insoluble solvents and then add suitable semi- I S p y parate out another 10 or 20* 0 Of polar compounds to give a homogeneous solubenzene by means of the phase-separating trap t and thus ra se e temperature 130 40 Another obvious procedure, of course, is merely (3-, 0 v to if e d be- My to distill ofi a solvent such as xylene or Solvent erence is not to go ab v #7-3 and then dissolve the product in a semi- The use of such solvent is extremely Sat polar solvent, such as methanol, ethanol, profactory provided One d not attempt to panol, etc. It is purely a matter of convenience move the solvent Su q y f p y 1 45 to first employ a non-polar solvent (water-indistillation and provided there is no ob ection bl t li i at th water during t to a little residue. Actually, when these malation and. then add a suitable polar solvent terials are used for a purpose such as demul- (hydrophile) to give a single-phase system.

TABLE 2 Th M 1. A t. r 116. E 115 4. 6 1661 w t ff 1 E1 0 330 013 3%, mi drozyl 0n ggg ycarboxy Ren t al xy Ester mm H C Hofo Value zctu al (gm) (Ernst) 16 970 115.5 199 564 DiglyCOliC Acid 92.6 16 970 115.5 199 564 195 OXflllCAOld 37.0 16 970 115.5 199 564 197 M31610 Anhydlide. 63.5 16 970 115.5 199 564 195 Phthfllifi Anhyd 102.0 16 970 115.5 199 564 196 CltlElCOlliC Anhyd. 73.0 16 970 115.5 199 564 195 AOODitiC .4616 120.5 26 1,300 62.4 167.5 670 205 D1 1 661i6 AOiCL. 32.0 26 1,300 62.4 167.5 670 203 Oxalic Acid 76.5 211 1,800 62.4 167.5 670 195 Maleic Anhydride 57.1 26 1,300 62.4 167.5 670 193 P11016116 Anhyd- 37.5 2a 1,800 62.4 167.5 670 205 Citraconic Anhy 68.5 26 1,300 62.4 167.5 070 199 ACOIlitiC A0id 103.5 36 3,040 36.9 92.6 1, 210 207 45.3 36 3,040 36.9 92.6 1,210 207 59.5 36 3,040 36.9 92.6 1,210 207 43.0 36 3,040 36.9 92.6 1,210 203 33.0 36 3,040 36.9 92.6 1, 210 207 33.2 36 3,040 36.9 92.6 1, 210 203 49.6 46 4,274 26.3 73.4 1, 530 205 36.0 46 4,274 26.3 73.4 1, 530 205 46.6 46 4,274 26.3 73.4 1,530 205 33.3 46 4,274 26.3 73.4 1,530 211 27.0 46 4,274 26.3 73.4 1,530 205 30.0 46 4,274 26.3 73.4 1,530 204 39.4 56 5, 734 26.3 73.4 1,530 210 27.5 56 5,734 26.3 73.4 1,530 210 25.3 56 5,734 26.3 73.4 1,530 210 20.1 56 5,734 26.3 73.4 1,530 210 PhthalicAnliyd 30.1 56 5,734 26.3 73.4- 1, 530 210 49061110 Acid 35.6

TABLE 3 Maximum m. No Amt. Esterifig gggf Water of Acid Solvent Solvent cation cation Out Ester (grs.) Temp, (hrs (cc.)

The procedure for manufacturing, the esters. has been illustrated by preceding examples. If for any reason reaction does not take. place ina manner that is acceptable, attention shouldbe directed to the following details: (a) Recheck the hydroxyl or acetyl value, of the oxypropylated derivative and use a stoichiometrically equivalent amount of acid; (b) If the reactiondoes not proceed with reasonable speed either raisev the temperature indicated or else extend the period of time up to 12 or 16 hours if need be; (c) If necessary, use /2% of paratoluene sulfonic acid or someother acid as. a. catalyst provided that the hydroxylated compound is not basic; (d). If the esterification does. not produce. a clear product a check should be made to see if an inorganic salt suchassodium chloride or sodium sulfate is not precipitating out. Such salt. should be. eliminated, at least for explorationexperimentation, and can be removed by filtering. Everything else being equal, as the size of the molecule increases and the reactive hydroxyl radical represents a smaller fraction of the entire molecule, more difficulty is involved in obtaining. complete esterification.

Even under the most carefully controlled con-.

ditions of oxypropylation involving comparatively low temperature and long time of reaction there of a polycarboxy acid with the oxypropylated.

derivative results in an excess of the carboxylated reactant for the reason that apparentlyunder conditions of reaction less reactive hydroxyl radicals are present than indicated by the hydroxyl value. Under such circumstances there issimply a residue of the carboxylic reactant which can.

be removed by filtration or, if desired; the esteri- Such side reaction, prodfication procedure can be repeated using an appropriately reduced ratio of .carboxylic reactant.

Even the determination of the 'hydroxyl value and conventional procedure leaves much, to be desired due either to thecogeneric materials previously referred to, or for that matter, the presence of any inorganic salts or propylene oxide. Obviously this oxide should Ice-eliminated.

The solvent employed, if any, can be removed from the finished ester by distillation and. particularly vacuum distillation. The final products. or liquids are generally strawto pale amber or dark amber in color, and show moderateviscosity. They can be bleached with bleaching clays, filtering chars, and the like. However, for the purpose of demulsification or the like color is not a factor and decolorization is not justified.

In the above instancev I have permitted the solvents to remain presentinthe final reaction mass. In other instances I have followed the same procedure using decalin or a mixture of decalin or benzene in the same manner and ultimately removed all the solvents by vacuum distillation. Appearances of the final products are much: the same as the poly-01s before esterification and in some instances were somewhat darker in color and had a reddish cast and perhaps were somewhat more viscous.

It is unnecessary to point out, of course, that what has been said herein is the same regardless of whether the initial material is a polyhydroxylated compound Or a compound containing a plurality of hydrogen atoms attached to nitrogen.

PART 3 In the hereto appended claims the demulsifying agent is described as an ester obtained from a polyhydroxylated material prepared from a diamine. If one were concerned with a monohydroxylated material or a dihydroxylated material one might be able to write a formula which in essence would represent the particular product. However, in a more highly hydroxylated material the problem becomes increasingly more difficult for reasons whichhave already been indicated in connection with oxypropylation and which can be examined by merely considering for the moment a monohydroxylated material.

Oxypropylation involves the same sort of variations as appear in preparing high molal polypropylene glycols. Propylene glycol has a secondary alcoholic radical and a primary alcohol radical. Obviously then polypropylene glycols could be obtained, at least theoretically, in which two secondary alcoholic groups are united or a secondary alcohol group is united to a primary alcohol group, etherization being involved, of.

course, in each instance. Needless to say, the same situation applies when one has oxypropylatedpolyhydric materials having 4 or more hydroxyls; or the obvious equivalent.

Usually no effort is made to differentiate between oxypropylation taking place, for example, at the primary alcohol radical or the secondary alcohol radical. are obtained, such as a high molal polypropylene glycol or the products obtained in the manner herein described one does not obtain a single derivative such as HO(RO)1:H or (RC)) all in which n has one and only one value, for instance, 14, 15 or 16, or the like. Rather, one obtains a cogeneric mixture of closely related or touching homologues. These materials invariably have molecular weights and cannot be separated from one. another by any known procedure without decomposition. The properties of such mixture represent the contribution of the various individual members of the mixture. On a statistical basis, of course, n can be appropriately specified. For practical purposes one need only consider the oxypropylation of a monohydric alcohol because in essence this is substantially the mechanism involved. Even in such instances where one is concerned with a monohydric reactant one cannot draw a single formula and say that by following such procedure one can readily obtain 80% or 90% or 100% of such compound. However, in the case of at least monohydric initial reactants one can readily draw the formulas of a large number of compounds which appear in some of the probable mixtures or can be prepared as components and mixtures which are manufactured conventionally.

Simply by way of illustration reference is made to the copending application of De Groote, Wirtel and Pettingill, Serial No. 109,791, filed August 11, 1949 (now Patent 2,549,434, granted April 17, 1951).

However, momentarily referring again toa monohydric initial reactant it is obvious that if one selects any such simple hydroxylated compound and subjects such compound to oxyalkylation, such as oxyethylations, or oxypropylation,

it: becomes obvious that one is really producing a polymer of the alkylene oxides except for the terminal group. This is particularly true where the amount of oxide added is comparatively large,- for instance, 10, 20, 30, 40, or 50 units. If such compound is subjected to oxyethylation so as to introduce 30 units of ethylene oxide, it

is well known that one does not obtain a single constituent which, for the sake of convenience, may be indicated as RO(C2H4O)30OH. Instead, one obtains a cogeneric mixture of closely related homologues, in which the formula may be shown as the following, RO(G2H4O)H, wherein, n. as far as the statistical average goes, is 30, but the individual members present in significant amount may vary from instances where n has a value of 25, and perhaps less, to a point where 11.

may. represent 35 or more. Such mixture is, as

Actually, when such products stated, a cogeneric closely related series of touching homologous compounds. Considerable investigation has been made in regard to the distribution curves for linear polymers. Attention is directed to the article entitled Fundamental Principles of Condensation Polymerization, by Flory, which appeared in Chemical Reviews, volume 39, No. 1, page 13'].

Unfortunately, as has been pointed out by Flory and other investigators, there is no satisfactory method, based on either experimental or mathematical examination, of indicating the exact proportion of the various members of touching homologous series which appear in cogeneric condensation products of the kind described. This means that from the practical standpoint, i. e., the ability to describe how to make the product under consideration and how to repeat such production time after time without difficulty, it is necessary to resort to some other method of description, or else consider the value of n, in formulas such as those which have appeared previously and which appear in the the average statistical value based on the assumption of completeness of reaction.

This may be illustrated as follows: Assumethat in any particular example the molal ratio of propylene oxide per hydroxyl is 15 to 1, In a generic formula 15 to 1 could be 10, 20 or some other amount and indicated by n. Referring to this specific case actually one obtains products in which it probably varies from 10 to 20, perhaps even further. The average value, however, is 15, assuming, as previously stated, that the reaction is complete. The product described by the formula is best described also in terms of method of manufacture.

The significant fact in regard to the oxypropylated polyamines herein described is that in the initial tage they are substantially all watersoluble, for instance, up to a molecular weight of 1,500 or thereabouts. Actually, such molecular Weight represents a mixture of some higher molecular weight materials and some lower molecular weight materials. The higher ones are probably water-insoluble. The product may tend to emulsify or disperse somewhat because some of the constituents, being a cogeneric mixture, are water-soluble but the .bulk are insoluble. Thus one gets emulsifiability or dispersibility as noted. Such products are invariably xylenesoluble regardless of whether the original reactants were or not. Reference is made to what has been said previously in regard to kerosenesolubility. For example, when the theoretical molecular weight gets somewhere past 4,000 or at approximately 5,000 the product is kerosenesoluble and water-insoluble. These kerosenesoluble oxyalkylation products are most desirable for preparing the esters. I have prepared hydroxylated compounds not only up to the theoretical molecular weight shown previously, 1. e., about 6,000 but also some which were much higher. I have prepared them, not only from propylenedi-amine, but also from oxyethylated or oxybutylated derivatives previously referred to. The exact composition is open to question for reasons which are common to all oxyalkylation. It is interesting to note, however, that the molecular weights based on hydroxyl determinaneighborhood of a, third or a fourth of the value 1 9 at maximum point. Referring again to previous data it is to be noted, however, that over the range shown of kerosene-solubility the hydroxyl molecular weight has invariably stayed at twothirds or five-eighths of the theoretical molecular weight.

It becomes obvious when carboxylic esters are prepared from such high molecular weight materials that the ultimate esterification product again must be a cogeneric mixture. Likewise, it is obvious that the contribution to the total molecular weight made by the polycarboxy acid is small. By the same token one would expect the effectiveness of the demulsifier to be comparable to the unesterified hydroxylated material. Remarkably enough, in many instances the product is distinctly better.

PART 4 Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or after dilution with' any suitable solvent, such as water, petroleum hydrocarbons, such as benzene, toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc., may be employed as diluents. Miscellaneous solvents such as pine oil, carbon tetrachloride, sulfur dioxide extract obtained in the refining of petroleum, etc., may be employed as diluents. Similarly, the material or materials employed as the demulsifying agent of my process may be admixed with one or more of the solvents customarily used in connection with conventional demulsifying agents. Moreover, said material or materials may be used alone or in admixture with other suitable Well-known classes of demulsifying agents.

It is well known that conventional demulsifying agents may be used in a water-soluble form, or in an oil-soluble form, or in a form exhibiting both 011- and water-solubility. Sometimes they may be used in a form which exhibits relatively limitedoil-solubility. However, since such reagents are frequently used in a ratio of l to 10,000 or 1 to 20,000, or 1 to 30,000, or even 1 to 40,000, or 1 to 50,000 as in desalting practice, such an apparent insolubility in oil and water is not significant because said reagents undoubtedly have solubility within such concentrations. This same fact is true in regard to the material or materials employed a the demulsifying agent of my process.

In practicing my process for resolving petroleum emulsions of the water-in-oil type, a treating agent or demulsifying agent of the kind above described is brought into contact with or caused to act upon the emulsion to be treated, in any of the Various apparatus now generally used to resolve or break petroleum emulsions with a chemical reagent, the above procedure being used alone or in combination with other demulsifying procedure, such as the electrical dehydration process.

One type of procedure is to accumulate a volume of emulsified oil in. a tank and conduct a batch treatment type of demulsification procedure to recover clean oil. In this procedure the emulsion is admixed with the demulsifier, for example by agitating the tank of emulsion and slowly dripping demulsifier into the emulsion. In some cases mixing is achieved by heating the emulsion while dripping in the demulsifier, depending upon the convention currentsin the emulsion to produce satisfactory admixture. In a third modification of this type of treatment, a circulating pump Withdraws emulsion from, e. g., the bottom of the tank, and reintroduces it into the top of the tank, the demulsifier being added, for example, at the suction side of said circulating pump.

In a second type of treating procedure, the demulsifier is introduced into the well fluids at the well-head or at some point between the well-head and the final oil storage tank, by means of an adjustable proportioning mechanism or proportioning pump. Ordinarily the flow of fluids through the subsequent lines and fittings sufiices to produce the desired degree of mixing of demulsifler and emulsion, although in some instances additional mixing devices may be introduced into the flow system. In this general procedure, the system may include various mechanical devices for withdrawing free water, separating "entrained water, or accomplishing quiescent settling of the chemicalized emulsion. Heating devices may likewise be incorporated in any of the treating procedures described herein.

A third type of application (down-the-hole) of demulsifier to emulsion is to introduce the demulsifier either periodically or continuously in diluted or undiluted form into the well and to allow it to come to the surface with the well fluids, and then to flow the chemicalized emulsion through any desirable surface equipment, such as employed in the other treating proce dures. This particular type of application is decidedly useful when the demulsifier is used in connection with acidification of calcareous oilbearing strata, especially if suspended in or dissolved in the acid employed for acidification.

In all cases, it will be apparent from the foregoing description, the broad process consists simply in introducing a relatively small propor- 'tion of demulsifier into a relatively large proporspecial apparatus, with or without the applica-.

tion of heat, and allowing the mixture to stand quiescent until the undesirable water content of the emulsion separates and settles from the mass.

The following is a typical installation. A reservoir to hold the demulsifier of the kind described (diluted or undiluted) is placed at the =well-head where the efliuent liquids leave the well. This reservoir or container, which may vary from 5 gallons to 50 gallons for convenience, is connected to a proportioning pump which injects the demulsifier drop-wise into the fluids leaving the well. Such chemicalized fluids pass through the flowline into a settling tank. The settling tank consists of a tank of any convenient size, for instance, one which will hold amounts of fluid produced in 4 to 24 hours (500 barrels to 2000 barrels capacity), and in which there is a perpendicular'conduit from the top of the tank to almost the very bottom so as to permit the incomingfluids to pass from the top of the settling tank to the bottom, so that such incoming fiuids do not disturb stratification which takes place during the course of demulsification. The settling tank has two outlets, one being below the water level to drain off the water resulting from demulsification or accompanying the emulsion as free water, the other being an oil outlet at the top to permit the'passage of dehydrated oil toa second tank, being a storage tank, which holds pipeline or dehydrated oil. If desired, the conduit to carry the-fluidsfrom the wellto the settling or pipe which serves" tank may include a section .of pipe with bafiles tov serve as a mixer, to insure thorough distribution of the demulsifier throughout the fluids,- or a heater for raising the temperature of the fluids to some convenient temperature, for instance, 120 to 160 F., or both heater and mixer.

Demulsification procedure is started by simply,

setting'the pump so as to feed a comparatively large ratio of demulsifier, for instance, 1:5,000. As soon as a complete break or satisfactory demulsification is obtained, the pump is regulated until experience shows .that the amount of de-' mulsifier being added is just sufiicient to produce clean or dehydrated oil. The amount being fed at such stage is usually 1110,000, '1:15,000, 1120,000, or the like.

In'many instances the oxyalkylated products herein specified as demulsifiers can be conven-v iently used Without dilution. However, as previously noted, they may be diluted as desired with any suitable solvent. For instance, by mixing '75 parts by weight of the product-of Example 1% with 15 parts by weight of xylene and. 10

parts by weight of isopropyl alcohol, an excellentv demulsifier is obtained. Selection of the solvent will vary,- depending'upon the solubility characteristics of the oxyalkylated product, and of course will be dictated in part by economic considerations, i. e., cost.

A noted above, the products herein described may be used not only in diluted form, but also may be used admixed with some-other chemical demulsifier. combination is the following:

Oxyalkylated derivative, for example, the prod-.

not of Example 191), 20%;

A cyclohexylamine salt of .a. po1ypropylated naphthalene monosulfonic acid, 24%;

An ammonium salt of a polypropylated naphthalene monosulfonic acid, 24%;

A sodium salt of oil-soluble mahogany petroleum sulfonic acid, 12%;

vA high-boiling aromatic petroleum solvent,

Isopropyl alcohol, 5%. I The above proportions are all weight percents. Having thus described my invention, what I claim asnew and desire to obtain by Letters Patent, is

1. A process for breaking petroleum emulsions of the water-in-oil type characterized by sub-' jecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products beinga cogeneric mixture selected from the class consisting of acidic fractional esters, acidic ester salts, and acidic amido derivatives obtained by reaction between (A) a polycarboxy acid, and (B) high molal oxypropylation derivatives of monomeric diamino compounds, with the proviso that (a) the initial diamino reactant be free from any radical having at least 8 uninterrupted carbon atoms; (b) the initial diamino reactant have.

a molecular weight of not over 800 and at least a. plurality of reactive hydrogen atoms; (0) .the initial diamino reactant must be water-soluble;

(d) the oxypropylation end product must be water-insoluble, and kerosene soluble; (e) the oxypropylation end product be within the molecular weight range of 2000 to 30,000 on an .average statistical basis; (I) the solubility characteristics of the oxypropylation end product in respect to water and kerosene must be substantially the result of the oxypropylation step; (g) the ratio of propylene oxide per initial reactive A mixture which illustrates such' hydrogen atom must be within the range of 7 to '70; (h) the initial diamino reactant must-represent not more than 20% by weight of the oxypropylation end product on a statistical basis; (2') the preceding provisos are based on the assumption of complete reaction involving the propylene oxide and initial diamino reactant;

(7') the nitrogen atoms are linked by a propylene chain, and with the final proviso that the ratio of (A) to (B) be one mole of (A) for each re--' active hydrogen atom present in (B).

2. A process for breaking petroleum emulsions of the water-in-oil type characterized by .subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being a cogeneric mixture selected from the class consisting ofv acidic fractional esters, acidic esterv salts, and;- acidic amido derivatives obtained by reaction be'-' tween (A) a polycarboxy acid and (B) high' molal oxypropylation derivatives of monomeric diamino compounds, with the proviso that (a)- the initial diamino reactant be free from any radical having at least 8 uninterrupted carbon atoms; (b) the initial diamino reactant having a molecular weight of not over 800 and at least a plurality of reactive hydrogen atoms; (0) the initial diamino reactant must be water-soluble; (d) the oxypropylation end product must be water-insoluble, and kerosene-soluble; (e) the oxypropylation end product be within the molecular weight range of 2000 to 30,000 on an average statistical basis; (1) the solubility-characteristics of the oxypropylation end product in respect to water and kerosene must be substantially the result of the oxypropylation step; (9) the ratio of propylene oxide per initial reactive hydrogen atom must be within the range of 7 to (h) the initial diamino reactant must represent not more than 20% by weight of the oxypropylation end product on a statistical basis; (2') the preceding provisos are based on the assumption of complete reaction involving the propylene oxide and initial diamino reactant;

(7') the nitrogen atoms are linked by a propylene chain; (It) at least one of the nitrogen atoms be basic, and with the final proviso that" the ratio of (A) to (B) be one mole of (A) for each reactive hydrogen atom present in (B).

3. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products;-

said hydrophile synthetic products being a cogeneric mixture selected from the class consisting of acidic fractional esters, acidic ester salts,

and acidic amido derivatives obtained by re-. action between (A) a polycarboxy acid and (B) high molal oxypropylation derivatives of monomeric diamino compounds, with the provisothat (a) the initial diamino reactant be free from any radical having at least 8 uninterrupted carbon atoms; (12) the initial diamino reactant have a molecular weight of not over 800 and at least a plurality of reactive hydrogen atoms; (0) the 1 initial diamino reactant must be water-soluble; (d) the oxypropylation end product must be water-insoluble, and kerosene-soluble; (e) the oxypropylation end product be within the molecular weight range of 2000 to 30,000 on an av- (f) the solubility char-' erage statistical basis; acteristics of the oxypropylation end product in respect to water and kerosene must be substantially the result of the oxypropylation step; (9) the ratio of propylene oxide per initial reactive as hydrogen atom must' be within the range. of '7; to 70; (h) the initial diamino reactant must represent not more than 20% by weight of the."

oxypropylation end product on a .statistical basis; (2') the preceding provisos are based on. therassumption of complete'reaction involving thepropylene oxide and initial diamino reactant; (j); the nitrogen atoms are linked by a. propylene. chain; (rk) that both nitrogen atoms bet basic: andwithzthefinal proviso that the ratio of (A). to (B) be one mole of (A) foreach reactiverhydrogen atomv present in (B).

4. A process for breaking petroleum emulsions.

of the.- water-in-oil type characterized by sub-o jecting the emulsion to the action of a demulsifier including hydrophile synthetic; products; saidwei h of; ot over d. at l a-s a u al t a ctive ymws ato t ni i l. diamino ac ant. mu e a ro e; he; oxypropylatign end product must be watersinsoluble, and kerosene-soluble; (e) the oxyprop-ylationend product be within the molecular weight range oi 20,00. to 30,000 on an. average statistical basis," (f) the solubility characteristics v of the oxyprq: pylation end product in respect. to waterand:

kerosene must be substantially the result of the.

oxypropylation step; g) the ratio of propylene oxide per initial reactive hydrogen atom must be. within the. range of, '7 to 70; (h) the. initial di amino. reactant must represent not more thanv 20% by weight of the oxypropylation end product, on a. statistical basis; (i) the preceding provisos are based onthe assumption of complete reaction involving the propylene oxide and initial diamino; reactant; (9') the nitrogen atoms are linked by a propylene chain; (k) that both nitrogen atoms. be basic; and with the. final proviso that theratio. of (A) to (B) be one mole of (A) for each reactive hydrogen atom presentin (B) A process for breaking petroleum emulsions. of the water-ineoil type, characterized by subjecting the emulsion to. theaction of ademulsifier including hydrophile synthetic products; hydrophile synthetic products being a. cogene ric. mixture selected from the class consisting of acidic fractional esters, acidic ester salts, and acidic amido derivatives obtained b reaction be: tween (A) a dicarboxy acid free from any radical having more than 8 uninterrupted carbon atoms in a single group, and (B) high molal xypropylati on derivatives of monomeric diamino cornpounds, with the proviso that (a) the initial d1;- amino reactant be free from any radical having at least 8 uninterrupted carbon atoms; (b) the initial diam'ino reactant having a molecular weight of not over 800 and at least a plurality of reactive hydrogen atoms; (0) the initial diamino reactant must be water-soluble; (d) the oxypropylation end product must be water-insoluble,

and kerosene-soluble; (e) the oxypropylation end product be within the molecular weight range of 2000 to 30,000 on an average statistical basis;-

(if)- the solubility characteristics-of the oxypropylationz end product in; respect to water and kerosene must be substan-tiallythe result of' the oxypropylation step; (9) the ratio ofpropylene oxide per initial reactivei'hydrogen atom must be. within the range of 7" to 70.; (h) the initial dis amino reactant. must. represent. not. more. than 20% by weightof the,oxypropylation.end'product ona statistical basis; (2') the=preceding provisos. are based onthe assumption of complete-reaction. involving thepropylene. oxide and initial diamino.

reactant; (9') the-nitrogen atoms are. linked by a propylene chain; (k) that: both nitrogen. atoms;

bezbasic; and with the final proviso that the ratio of (A) to, (B) beone mole of (A) for each'reactive hydrogen atom present in (B).

6:; A process. for; breaking petroleum emulsions of the. water-in-oil type characterized by sub, jecting the. emulsion to. the action. of' a demulsi-.-v fier including hydrophile synthetic" products said hydrophile synthetic products being a cogeneric; mixture selected; from. the class consisting of" acidic fractional esters, acidic ester salts, and acidic amido. derivatives obtained by reactionbetween. (A) a dicarboxy acid free from any'radical having. more. than 8: uninterrupted carbon atoms in a single group, and (B) high molal oxyproe pylation. derivatives of.- propylenediamine; with the proviso that (a) the oxypropylation end prod'- uct. must. be water-insoluble and kerosene-soluble; (b).v theoxypropylation endproduct be with! in the molecular weight. range of 2000 to 30,000

must represent not more than 20% by weight of the oxypropylation end product on a statistical basis; (f) the preceding provisos are based on the. assumption of: complete" reaction involving the propylene oxide and initial 'diamino reactant;

. and with the final provisothat-the. ratio, of (A) to. (B) beone mole of; (A) for-each reactivehyr san tqm pre en n.

7. The process of claim. Gwherein the dicarboxy acid is diglycollic acid.

ezn qcess. Q -f la m: fi ere t e dica h y acid; is maleic.acid-..

9,. Theprocess-otclaim; 6 wherein the dicarboxy" acid is .phthali cacid.

10, Theprocessxof; claimfi; wherein; the dicarbox-r ac is it a onic. c

1:1,. The; processof claim 6 wherein the diOBJf-x boxy. acid iasuccinic acid.

i MELVIN DE GRQOTE ma k. Witnesses tomark -z W. C, ADAMS, I S. .13 Gnoorn.

REE E NQES Q TED.

The following references are ofrecord in the;

file of; thi patent;

UNITED STATES PATENTS 

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE CHARACTEIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIER INCLUDING HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETIC PRODUCTS BEING A COGNERIC MIXTURE SELECTED FROM THE CLASS CONSISTING OF ACIDIC FRACTIONAL ESTERS, ACIDIC ESTER SALTS, AND ACIDIC AMIDO DERIVATIVES OBTAINED BY REACTION BETWEEN (A) A POLYCARBOXY ACID, AND (B) HIGH MOLAL OXYPROPYLATION DERIVATIVES OF MONOMERIC DIAMINO COMPOUNDS, WITH THE PROVISO THAT (A) THE INITIAL DIAMINO REACTANT BE FREE FROM ANY RADICAL HAVING AT LEAST 8 UNINTERRUPTED CARBON ATOMS; (B) THE INITIAL DIAMINO REACTANT HAVE A MOLECULAR WEIGHT OF NOT OVER 800 AND AT LEAST A PLURALITY OF REACTIVE HYDROGEN ATOMS; (C) THE INITIAL DIAMINO REACTANT MUST BE WATER-SOLUBLE; (D) THE OXYPROPYLATION END PRODUCT MUST BE WATER-INSOLUBLE, AND KEROSENE SOLUBLE; (E) THE OXYPROPYLATION END PRODUCT BE WITHIN THE MOLECULAR WEIGHT RANGE OF 2000 TO 30,000 ON AN AVERAGE STATISTICAL BASIS; (F) THE SOLUBILITY CHARACERTISTICS OF THE OXYPROPYLATION END PRODUCT IN RESPECT TO WATER AND KEROSENE MUST BE SUBSTANTIALLY THE RESULT OF THE OXYPROPYLATION STEP; (G) THE RATIO OF PROPYLENE OXIDE PER INITIAL REACTIVE HYDROGEN ATOM MUST BE WITHIN THE RANGE OF 7 TO 70; (H) THE INITIAL DIAMINO REACTANT MUST REPRESENT NOT MORE THAN 20% BY WEIGHT OF THE OXYPROPYLATION END PRODUCT ON A STATISTICAL BASIS; (I) THE PRECEDING PROVISOS ARE BASED ON THE ASSUMPTION OF COMPLETE REACTION INVOLVING THE PROPYLENE OXIDE AND INITIAL DIAMINO REACTANT; (J) THE NITROGEN ATOMS ARE LINKED KBY A PROPYLENE CHAIN, AND WITH THE FINAL PROVISO THAT THE RATIO OF (A) TO (B) BE ONE MOLE OF (B) FOR EACH REACTIVE HYDROGEN ATOM PRESENT IN (B). 